Bicycle crank arm portion



FIG. 1 is a perspective view of the bicycle crank arm portion in accordance with my new design;

FIG. 2 is a front elevational view of the bicycle crank arm portion in accordance with my new design;

FIG. 3 is a left side elevational view of the bicycle crank arm portion in accordance with my new design;

FIG. 4 is a right side elevational view of the bicycle crank arm portion in accordance with my new design; and,

FIG. 5 is a top plan view of the bicycle crank arm portion in accordance with my new design.

The broken line showing of environment (the remaining structure of the bicycle crank arm portion) in the Figures is for illustrative purposes only and forms no part of the claimed design. The rear and bottom sides of the bicycle crank arm portion do not form part of the claimed design. 

The ornamental design for a bicycle crank arm portion, as shown and described. 